Public Support for Increased Trade, Except With South Korea and China

Fewer See Benefits from Free Trade Agreements

About the Surveys

Most of the analysis in this release is based on telephone interviews conducted November 4-7, 2010 among a national sample of 1,255 adults 18 years of age or older living in the continental United States as part of the Pew Research Center’s biennial post-election survey (828 respondents were interviewed on a landline telephone, and 427 were interviewed on a cell
phone, including 189 who had no landline telephone). Interviewing was conducted under the direction of Princeton Survey Research Associates International. Both the landline and cell phone samples were provided by Survey Sampling International. Interviews were conducted in English. For detailed information about our survey methodology, see:http://www.people-press.org/methodology/

The combined landline and cell phone sample are weighted using an iterative technique that matches gender, age, education, race/ethnicity, region, and population density to parameters from the March 2009 Census Bureau’s Current Population Survey. The sample also is weighted to match current patterns of telephone status and relative usage of landline and cell phones (for those with both), based on extrapolations from the 2009 National Health Interview Survey. The weighting procedure also accounts for the fact that respondents with both landline and cell phones have a greater probability of being included in the combined sample and adjusts for household size within the landline sample. Sampling errors and statistical tests of significance take into account the effect of weighting. The following table shows the error attributable to sampling that would be expected at the 95% level of confidence for different groups in the survey:

In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.

Along with the main survey described above, this report is supplemented with a weekly omnibus poll. Results for this survey are based on telephone interviews conducted under the direction of Princeton Survey Research Associates International among a national sample of 996 adults living in the continental United States, 18 years of age or older, from November 4-November 7, 2010 (666 respondents were interviewed on a landline telephone, and 330 were interviewed on a cell phone, including 160 who had no landline telephone). Both the landline and cell phone samples were provided by Survey Sampling International. Interviews were conducted in English.

The combined landline and cell phone sample are weighted using an iterative technique that matches gender, age, education, race, Hispanic origin, region, and population density to parameters from the March 2009 Census Bureau’s Current Population Survey. The sample is also weighted to match current patterns of telephone status based on extrapolations from the 2009 National Health Interview Survey. The weighting procedure also accounts for the fact that respondents with both landline and cell phones have a greater probability of being included in the combined sample and adjusts for household size within the landline sample. Sampling errors and statistical tests of significance take into account the effect of weighting. The following table shows the error attributable to sampling that would be expected at the 95% level of confidence for different groups in the survey:

In addition to sampling error, one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls.

About Pew Research Center Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping America and the world. It conducts public opinion polling, demographic research, media content analysis and other empirical social science research. Pew Research Center does not take policy positions. It is a subsidiary of The Pew Charitable Trusts.